Device and method for modifying the shape of a body organ

ABSTRACT

An intravascular support device includes a support or reshaper wire, a proximal anchor and a distal anchor. The support wire engages a vessel wall to change the shape of tissue adjacent the vessel in which the intravascular support is placed. The anchors and support wire are designed such that the vessel in which the support is placed remains open and can be accessed by other devices if necessary. The device provides a minimal metal surface area to blood flowing within the vessel to limit the creation of thrombosis. The anchors can be locked in place to secure the support within the vessel.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] The present application is a continuation-in-part of U.S.application Ser. No. 10/331,343, filed Dec. 26, 2002; U.S. applicationSer. No. 10/142,637, filed May 8, 2002; U.S. application Ser. No.10/066,426, filed Jan. 30, 2002; and U.S. application Ser. No.10/011,867, filed Dec. 5, 2001, the benefit of the filing dates beingclaimed under 35 U.S.C. § 120, and the disclosures of which areincorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to medical devices in general, andin particular to devices for supporting internal body organs.

BACKGROUND OF THE INVENTION

[0003] The mitral valve is a portion of the heart that is locatedbetween the chambers of the left atrium and the left ventricle. When theleft ventricle contracts to pump blood throughout the body, the mitralvalve closes to prevent the blood being pumped back into the leftatrium. In some patients, whether due to genetic malformation, diseaseor injury, the mitral valve fails to close properly causing a conditionknown as regurgitation, whereby blood is pumped into the atrium uponeach contraction of the heart muscle. Regurgitation is a serious, oftenrapidly deteriorating, condition that reduces circulatory efficiency andmust be corrected.

[0004] Two of the more common techniques for restoring the function of adamaged mitral valve are to surgically replace the valve with amechanical valve or to suture a flexible ring around the valve tosupport it. Each of these procedures is highly invasive because accessto the heart is obtained through an opening in the patient's chest.Patients with mitral valve regurgitation are often relatively frailthereby increasing the risks associated with such an operation.

[0005] One less invasive approach for aiding the closure of the mitralvalve involves the placement of a support structure in the cardiac sinusand vessel that passes adjacent the mitral valve. The support structureis designed to push the vessel and surrounding tissue against the valveto aid its closure. This technique has the advantage over other methodsof mitral valve repair because it can be performed percutaneouslywithout opening the chest wall. While this technique appears promising,some proposed supports appear to limit the amount of blood that can flowthrough the coronary sinus and may contribute to the formation ofthrombosis in the vessel. Therefore, there is a need for a tissuesupport structure that does not inhibit the flow of blood in the vesselin which it is placed and reduces the likelihood of thrombosisformation. Furthermore, the device should be flexible and securelyanchored such that it moves with the body and can adapt to changes inthe shape of the vessel over time.

SUMMARY OF THE INVENTION

[0006] The present invention is an intravascular support that isdesigned to change the shape of a body organ that is adjacent to avessel in which the support is placed. In one embodiment of theinvention, the support is designed to aid the closure of a mitral valve.The support is placed in a coronary sinus and vessel that are locatedadjacent the mitral valve and urges the vessel wall against the valve toaid its closure.

[0007] The intravascular support of the present invention includes aproximal and distal anchor and a support wire or reshaper disposedtherebetween. The proximal and distal anchors circumferentially engage avessel in which the support is placed. A support wire is urged againstthe vessel by the proximal and distal anchors to support the tissueadjacent the vessel.

[0008] In one embodiment of the invention, the proximal and distalsupports are made from a wire hoop that presents a low metal coveragearea to blood flowing within the vessel. The wire hoops may allow tissueto grow over the anchors to reduce the chance of thrombosis formation.The wire hoops have a figure eight configuration and can expand tomaintain contact with the vessel walls if no vessel expands or changesshape.

[0009] In another embodiment of the invention, the proximal and distalanchors of the intravascular support are rotationally offset from eachother. Locks on the support wire allow a physician to ensure that theanchors have been successfully deployed and prevent the support wirefrom collapsing within a vessel.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The foregoing aspects and many of the attendant advantages ofthis invention will become more readily appreciated as the same becomebetter understood by reference to the following detailed description,when taken in conjunction with the accompanying drawings, wherein:

[0011]FIG. 1 illustrates an intravascular support for changing the shapeof an internal body organ in accordance with one embodiment of thepresent invention;

[0012]FIG. 2 illustrates one method of deploying an intravascularsupport in accordance with the present invention;

[0013]FIG. 3 illustrates one embodiment of the intravascular support inaccordance with the present invention;

[0014]FIG. 4 illustrates a distal anchor of the embodiment shown in FIG.3;

[0015]FIG. 5 illustrates a proximal anchor of the embodiment shown inFIG. 3;

[0016] FIGS. 6A-6C are cross-sectional views of crimp tubes for use withone embodiment of the present invention;

[0017]FIG. 7 illustrates a proximal lock at the proximal end of theintravascular support as shown in FIG. 3;

[0018]FIG. 8 illustrates how the embodiment of the intravascular supportshown in FIG. 3 is deployed from a catheter;

[0019]FIG. 9 illustrates an intravascular support in accordance withanother embodiment of the present invention;

[0020]FIG. 10 illustrates a distal anchor of the intravascular supportshown in FIG. 9;

[0021]FIG. 11 illustrates a proximal anchor of the intravascular supportshown in FIG. 9;

[0022]FIG. 12 illustrates yet another embodiment of an intravascularsupport in accordance with the present invention;

[0023]FIG. 13 illustrates a distal anchor of the intravascular supportshown in FIG. 12;

[0024]FIG. 14 illustrates a proximal anchor of the intravascular supportshown in FIG. 12;

[0025]FIG. 15 illustrates an anchor and strut according to anotherembodiment of the invention;

[0026]FIG. 16 illustrates a double loop anchor according to anotherembodiment of the invention;

[0027]FIG. 17 illustrates a double loop anchor with a cross strutaccording to another embodiment of the invention; and

[0028]FIG. 18 illustrates an anchor with torsional springs according toanother embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0029] As indicated above, the present invention is a medical devicethat supports or changes the shape of tissue that is adjacent a vesselin which the device is placed. The present invention can be used in anylocation in the body where the tissue needing support is located near avessel in which the device can be deployed. The present invention isparticularly useful in supporting a mitral valve in an area adjacent acoronary sinus and vessel. Therefore, although the embodiments of theinvention described are designed to support a mitral valve, thoseskilled in the art will appreciate that the invention is not limited touse in supporting a mitral valve.

[0030]FIG. 1 illustrates a mitral valve 20 having a number of flaps 22,24, and 26 that should overlap and close when the ventricle of the heartcontracts. As indicated above, some hearts may have a mitral valve thatfails to close properly thereby creating one or more gaps 28 that allowblood to be pumped back into the left atrium each time the heartcontracts. To add support to the mitral valve such that the valvecompletely closes, an intravascular support 50 is placed in a coronarysinus and vessel 60 that passes adjacent one side of the mitral valve20. The intravascular support 50 has a proximal anchor 52, a distalanchor 54, and a support wire 56 or reshaper extending between theproximal and distal anchors. With the anchors 52 and 54 in place, thesupport wire 56 exerts a force through the coronary sinus wall on thepostero-lateral mitral valve 20 thereby closing the one or more gaps 28formed between the valve flaps. With the intravascular support 50 inplace, the function of the mitral valve is improved.

[0031] As will be explained in further detail below, each of theproximal and distal anchors 52, 54 preferably circumferentially engagesthe wall of the vessel 60 in which it is placed. The support wire 56 issecured to a peripheral edge of the proximal and distal anchors suchthat the support wire is urged by the anchors against the vessel wall.Therefore, the support wire 56 and anchors 52, 54 present a minimalobstruction to blood flowing within the vessel.

[0032]FIG. 2 shows one possible method of delivering the intravascularsupport of the present invention to a desired location in a patient'sbody. An incision 80 is made in the patient's skin to access a bloodvessel. A guide catheter 82 is advanced through the patient'svasculature until its distal end is positioned adjacent the desiredlocation of the intravascular support. After positioning the guidecatheter 82, a delivery catheter and advancing mechanism 84 are insertedthrough the guide catheter 82 to deploy the intravascular support at thedesired location in the patient's body. Further detail regarding onesuitable advancing mechanism 84 is described in commonly assigned U.S.patent application Ser. No. 10/313,914, filed Dec. 5, 2002, thedisclosure of which is hereby incorporated by reference.

[0033]FIG. 3 illustrates one embodiment of an intravascular support inaccordance with the present invention. The intravascular support 100includes a support wire 102 having a proximal end 104 and a distal end106. The support wire 102 is made of a biocompatible material such asstainless steel or a shape memory material such as nitinol wire.

[0034] In one embodiment of the invention, the support wire 102comprises a double length of nitinol wire that has both ends positionedwithin a distal crimp tube 108. To form the support wire 102, the wireextends distally from the crimp tube 108 where it is bent to form adistal stop loop (see 121 in FIG. 4) having a diameter that is largerthan the lumens within the distal crimp tube 108. After forming thedistal stop loop, the wire returns proximally through the crimp tube 108towards the proximal end of the support 100. Proximal to the proximalend of the crimp tube 108, is a distal lock 110 that is formed by thesupport wire bending away from the longitudinal axis of the support 102and then being bent parallel to the longitudinal axis of the supportbefore being bent again towards the longitudinal axis of the support.Therefore, the bends in the support wire form a half 110 a of the distallock that is used to secure the distal anchor in the manner describedbelow. From the distal lock 110, the wire continues proximally through aproximal crimp tube 112. On exiting the proximal end of the proximalcrimp tube 112, the wire is bent to form an arrowhead-shaped proximallock 114. The wire of the support 102 then returns distally through theproximal crimp tube 112 to a position just proximal to the proximal endof the distal crimp tube 108 wherein the wire is bent to form a secondhalf 110 b of the distal lock 110.

[0035] Support wire 102 has a length that is selected based on itsintended destination within a patient's vessel. For use in supporting amitral valve, the support wire is preferably between one and six incheslong and has a curved bend between its proximal end 104 and distal end106 with a radius of curvature between 1 and 3 inches and mostpreferably with a radius of curvature of 1.8 inches. In addition, thewire used to form the support wire 102 is flexible enough to move witheach heartbeat (thereby changing the force applied to the mitral valveannulus during the heartbeat) and stiff enough to support the mitralvalve. In one embodiment, the wire used to form the support wire 102 ismade of nitinol having a modulus of elasticity of 5-20×10⁶ psi and adiameter of between 0.0110″ and 0.0150″ and most preferably 0.0140″.Other shape memory materials may be used for support wire as well.

[0036] At the distal end of the support wire 102 is a distal anchor 120that is formed of a flexible wire such as nitinol or some other shapememory material. As is best shown in FIGS. 3 and 4, the wire forming thedistal anchor has one end positioned within the distal crimp tube 108.After exiting the distal end of the crimp tube 108, the wire forms afigure eight configuration whereby it bends upward and radially outwardfrom the longitudinal axis of the crimp tube 108. The wire then bendsback proximally and crosses the longitudinal axis of the crimp tube 108to form one leg of the figure eight. The wire is then bent to form adouble loop eyelet or loop 122 around the longitudinal axis of thesupport wire 102 before extending radially outwards and distally backover the longitudinal axis of the crimp tube 108 to form the other legof the figure eight. Finally, the wire is bent proximally into thedistal end of the crimp tube 108 to complete the distal anchor 120.

[0037] The distal anchor is expanded by sliding the double eyelet 122 ofthe distal anchor from a position that is proximal to the distal lock110 on the support wire to a position that is distal to the distal lock110. The bent-out portions 110 a and 110 b of support wire 110 arespaced wider than the width of double eyelet 122 and provide cammingsurfaces for the locking action. Distal movement of eyelet 122 pushesthese camming surfaces inward to permit eyelet 122 to pass distally ofthe lock 110, then return to their original spacing to keep eyelet 122in the locked position.

[0038] The dimensions of the distal anchor are selected so that thediameter of the distal anchor in a plane perpendicular to the axis ofthe lumen in which the anchor is deployed is preferably between 100% and300%, most preferably between 130% and 200%, of the diameter of thelumen prior to deployment. When treating mitral valve regurgitation byplacement of the device in the coronary sinus, the diameter of thecoronary sinus may expand over time after deployment. Oversizing theanchor combined with the inherent deformability and recoverabilityproperties of the anchor material (particularly nitinol or some othershape memory material) enables the anchor to continue to expand from itsinitial deployment size as the lumen distends and expands over time.

[0039] Upon expansion, the distal anchor circumferentially engages thevessel wall with a radially outwardly directed force that is distributedunequally around the circumference of the anchor by distending thevessel wall in variable amounts along the axial length of the anchor.The unequal distribution of force helps the anchor contact the lumenwall securely by creating bumps and ridges that are not parallel to thecentral axis of the lumen. In its expanded configuration, the distalanchor's diameter is at least 50%-500% and most preferably 100%-300% ofthe anchor's diameter in the unexpanded configuration. The opencross-sectional area of the lumen through the anchor is at least 50%,and most preferably 80%-100% of the lumen cross-sectional area prior toredeployment of the anchor.

[0040] In addition, the metal coverage of the anchor, as defined by thepercentage of the lumen surface area through which the anchor extendsthat is exposed to a metal surface, is between 5% and 30% and mostpreferably 10%. The wire used to form the distal anchor 120 ispreferably nitinol having a diameter of between 0.0110″ and 0.0150″ andmost preferably 0.0140 inches. Other shape memory materials may be usedas well.

[0041] During insertion, a physician can tactilely feel when the eyelet122 has been slid over the distal lock 110 in order to determine whenthe distal anchor has been set within a vessel lumen. In addition, ifthe anchor is misplaced, it can be collapsed by pulling the eyelet 122proximally over the distal lock 110 and repositioning the anchor in theunexpanded configuration. The force required to capture the distalanchor is preferably less than 20 lbs. and more preferably less than 10lbs.

[0042]FIG. 4 also illustrates how the crimp tube 108 is held in placebetween the distal lock 110 on the proximal side and the stop loop 121at the distal end of the support wire 102. The wires of the distalanchor 120 exit the distal end of the crimp tube 108 at an angle ofapproximately 45 degrees before looping back over the length of thedistal crimp tube 108. Therefore, the distal end of the anchor isrelatively a traumatic to avoid damage to a vessel during placement.

[0043] At the proximal end of the intravascular support is a proximalanchor 140 that is preferably formed of a biocompatible, elastic wiresuch as stainless steel or a shape memory material such as nitinol. Asis best shown in FIGS. 3 and 5, the proximal anchor 140 in oneembodiment is made of a single length of wire having a first endpositioned within a proximal crimp tube 112. The wire extends distallyfrom the crimp tube 112 and bends radially outward and away from thelongitudinal axis of the crimp tube 112 before being bent proximally andcrossing the longitudinal axis of the crimp tube 112 in order to form afirst leg of a figure eight configuration. The wire then is bent to forma double eyelet or loop 142 around the longitudinal axis of the supportwire 102 wherein the eyelet 142 has a diameter that allows it to beforced over the proximal lock 114. After forming the eyelet 142, thewire extends outwardly and away from the longitudinal axis of the crimptube 112 before being bent distally over and across the longitudinalaxis of the crimp tube 112 to form the second leg of a figure eight.Finally, the wire is bent proximally and extends into the distal end ofthe crimp tube 112.

[0044] Like the distal anchor, the proximal anchor is expanded andlocked by sliding the double eyelet 142 of the proximal anchor from aposition that is proximal to the proximal lock 114 on the support wireto a position that is distal to the proximal lock 114. As can be seen inFIG. 7, the proximal lock 114 has an “arrowhead” shape whereby theproximal end of the lock is bent away from the longitudinal axis of thesupport wire at an angle that is less steep than the distal end of theproximal lock. The less steep section makes it easier to advance theeyelet 142 over the lock in the distal direction than to retrieve theeyelet 142 over the proximal lock 114 in the proximal direction. Distalmovement of eyelet 142 cams the less steep proximal surfaces inward topermit eyelit 142 to pass distally of the lock 114, then return to theiroriginal spacing to keep eyelet 142 in the locked position.

[0045] As can be seen by comparing the proximal anchor 140 with thedistal anchor 120 in FIG. 3, the proximal anchor has a larger radius ofcurvature because it is designed to fit within a larger diameter portionof the coronary sinus. The dimensions of the proximal anchor areselected so that the diameter of the proximal anchor in a planeperpendicular to the axis of the lumen in which the anchor is deployedis preferably between 100% and 300%, most preferably between 130% and200%, of the diameter of the lumen prior to deployment. As with thedistal anchor, oversizing the proximal anchor combined with the inherentdeformability and recoverability properties of the anchor material(particularly nitinol or some other shape memory material) enables theanchor to continue to expand from its initial deployment size as thelumen distends and expands over time.

[0046] Upon expansion, the proximal anchor circumferentially engages thevessel wall with a radially outwardly directed a force that isdistributed unequally around the circumference of the anchor bydistending the vessel wall in variable amounts along the axial length ofthe anchor. As with the distal anchor, the unequal distribution of forcehelps the proximal anchor contact the lumen wall securely by creatingbumps and ridges that are not parallel to the central axis of the lumen.In its expanded configuration, the proximal anchor's diameter is atleast 50%-500% and most preferably 100%-300% of the anchor's diameter inthe unexpanded configuration. The open cross-sectional area of the lumenthrough the anchor is at least 50% and most preferably 80%-100% of thelumen cross sectional area prior to redeployment of the anchor.

[0047] In one embodiment of the invention, the proximal and distalanchors are oriented such that the planes of the anchors are offset withrespect to each other by an angle of approximately 30 degrees. Theoffset helps the intravascular support 100 seat itself in the coronarysinus and vessel surrounding the mitral valve in certain mammals.However, it will be appreciated that if the support is designed forother uses, the proximal and distal anchors may be offset by more orless depending upon the anatomy of the intended destination.

[0048] FIGS. 6A-6C illustrate cross-sectional views of the crimp tubesin which the wires that form the support wire 102 and proximal anddistal anchors 120, 140 are threaded. In one embodiment, the crimp tubescomprise a biocompatible material such as titanium having a number ofholes extending longitudinally through the tube through which the wiresare threaded. In FIG. 6A, a tube 150 has four holes 152, 154, 156, 158positioned in approximately a square configuration within thecircumference of the tube 150. As shown in FIG. 6B, a tube 160 includesfour holes 162, 164, 166, 168 therein that are positioned in a diamondconfiguration. FIG. 6C shows another tube 170 having four holes 172,174, 176, 178. Here the holes 172, 174 lie in a first plane and thesecond pair of holes 176, 178 lie in a second plane that is offset fromthe plane of the holes 172, 174. By changing the orientation of theholes 176, 178 with respect to the holes 172, 174, the relative plane ofwires passing through the holes can be adjusted. Thus in the exampleshown in FIG. 3, the proximal anchor may be formed with a crimp tubesuch as that shown in FIG. 6A or FIG. 6B while the proximal anchor maybe formed in a crimp tube such as that shown in FIG. 6C in order toadjust the angular orientation between the proximal anchor and thedistal anchor. In an alternative embodiment, the crimp tubes at theproximal and distal ends of the support wire 102 are the same and theangular offset between the proximal and distal anchor is achieved bybending the wires at the desired angle. Although the crimp tubes shownuse one hole for each wire passing through the crimp tube, it will beappreciated that other configurations may be provided such as slots orother passages for the wires to pass through.

[0049] In another embodiment, the distal and proximal anchors areattached to the support wire by a wire, such as nitinol wire or othershape memory material. The attaching wire may be spiral wrapped aroundthe base of each anchor and around the support wire. In anotherembodiment, each anchor may be attached to the support wire by wrappingthe anchor wire around the support wire. In yet another embodiment, thetwo anchors and the support wire may be made from a single wire, such asnitinol wire or other shape memory material.

[0050]FIG. 8 illustrates one method for delivering an intravascularsupport 100 in accordance with the present invention to a desiredlocation in the body. As indicated above, intravascular support 100 ispreferably loaded into and routed to a desired location within acatheter 200 with the proximal and distal anchors in a collapsed ordeformed condition. That is, the eyelet 122 of the distal anchor 120 ispositioned proximally of the distal lock 110 and the eyelet 142 of theproximal anchor 140 is positioned proximal to the proximal lock 114. Thephysician ejects the distal end of the intravascular support from thecatheter 200 into the lumen by advancing the intravascular support orretracting the catheter or a combination thereof. A pusher (not shown)provides distal movement of the intravascular support with respect tocatheter 200, and a tether 201 provides proximal movement of theintravascular support with respect to catheter 200. Because of theinherent recoverability of the material from which it is formed, thedistal anchor begins to expand as soon as it is outside the catheter.Once the intravascular support is properly positioned, the eyelet 122 ofthe distal anchor is pushed distally over the distal lock 110 so thatthe distal anchor 120 further expands and locks in place to securelyengage the lumen wall and remains in the expanded condition. Next, theproximal end of the support wire 102 is tensioned by applying aproximally-directed force on the support wire and distal anchor to applysufficient pressure on the tissue adjacent the support wire to modifythe shape of that tissue. In the case of the mitral valve, fluoroscopy,ultrasound or other imaging technology may be used to see when thesupport wire supplies sufficient pressure on the mitral valve to aid inits complete closure with each ventricular contraction without otherwiseadversely affecting the patient. A preferred method of assessingefficacy and safety during a mitral valve procedure is disclosed incopending U.S. patent application Ser. No. 10/366,585, filed Feb. 12,2003, and titled “Method of Implanting a Mitral Valve Therapy Device,”the disclosure of which is incorporated herein by reference. Once theproper pressure of the support wire has been determined, the proximalanchor is deployed from the catheter and allowed to begin its expansion.The eyelet 142 of the proximal anchor 140 is advanced distally over theproximal lock 114 to expand and lock the proximal anchor, therebysecurely engaging the lumen wall and maintaining the pressure of thesupport wire against the lumen wall. Finally, the mechanism for securingthe proximal end of the intravascular support can be released. In oneembodiment, the securement is made with a braided loop 202 at the end oftether 201 and a hitch pin 204. The hitch pin 204 is withdrawn therebyreleasing the loop 202 so it can be pulled through the proximal lock 114at the proximal end of the intravascular support 100.

[0051] In many contexts, it is important for the device to occupy aslittle of the lumen as possible. For example, when using the device andmethod of this invention to treat mitral valve regurgitation, the deviceshould be as open as possible to blood flow in the sinus (and to theintroduction of other medical devices, such as pacing leads) while stillproviding the support necessary to reshape the mitral valve annulusthrough the coronary sinus wall. The combination of the device's opendesign and the use of nitinol or some other shape memory materialenables the invention to meet these goals. When deployed in the coronarysinus or other lumen, the device preferably occupies between about 1.5%and about 1.5% of the overall volume of the section of lumen in which itis deployed.

[0052] In many embodiments of the invention, the use of a shape memorymaterial such as nitinol is particularly important. The percentage ofshape memory material by volume in the device is preferably betweenabout 30% and 100%, most preferably between about 40% and 60%.

[0053] In some instances, it may be necessary to move or remove anintravascular support after deployment by recapturing the device into acatheter. Prior to deployment of the proximal anchor, the distal anchormay be recaptured into the delivery catheter by simultaneously holdingthe device in place with tether 201 while advancing catheter distallyover distal anchor 120 so that the entire device is once again insidecatheter 200. The distally directed force of the catheter collapsesdistal anchor 120 into a size small enough to fit into catheter 200again. Likewise, after deployment of both anchors but prior to releasingthe securement mechanism as described above, the intravascular supportmay be recaptured into the delivery catheter by simultaneously holdingthe device in place with tether 201 while advancing catheter distallyfirst over proximal anchor 140, over support wire 102, and finally overdistal anchor 120. The distally directed forced of catheter 200collapses anchors 120 and 140 into a size small enough to fit intocatheter 200 again. If the securement mechanism has been detached fromthe device prior to recapture, the device still may be recaptured intothe delivery catheter or another catheter by grasping the proximal endof the device with a grasper or tether and by advancing the catheterdistally over the device.

[0054] In one embodiment of the invention, proximal anchor 140 includesa recapture guidance and compression element. In the embodiment shown inFIG. 5, the slope of the two proximal arms 143 and 144 of proximalanchor 140 is small in proximal portions 145 and 146 of the arms, thenincreases in more distal portions 147 and 148 of the arms. This shapeguides the catheter to move distally over the anchor more easily and tohelp compress the anchor to a collapsed shape as the catheter advancesduring recapture.

[0055] Likewise, the two proximal arms 123 and 124 of distal anchor 120have a shallower slope in their proximal portions 145 and 146 and anincreased slope in more distal portions 147 and 148. While recapture ofthe distal anchor is somewhat easier due to its smaller size compared tothe proximal anchor, this recapture guidance and compression featureenhances the ease with which recapture is performed.

[0056]FIG. 9 illustrates an alternative embodiment of the intravascularsupport of the present invention. In this embodiment, an intravascularsupport 250 has a support wire 252 and a distal anchor 254 and aproximal anchor 256. In the embodiment shown in FIG. 9, the distalanchor 254 is made from the same wire used to form the support wire 252.As best shown in FIG. 10, the wire used to form the support wire 252extends distally through a distal crimp tube 260 before looping radiallyoutward and returning proximally and across the longitudinal axis of thecrimp tube 260 to form one leg of a figure eight. The wire then windsaround the axis of the suspension wire 252 to form an eyelet 262. Thewire then continues radially outward and distally across thelongitudinal axis of the crimp tube 260 to form the second leg of afigure eight. After forming the figure eight, the wire enters the distalend of the crimp tube 260 in the proximal direction to form the otherhalf of the support wire 252. A distal lock 264 is formed proximal tothe distal crimp tube 260 by outwardly extending bends in the wires thatform the support wire 252. The distal lock 264 prevents the doubleeyelet 262 from sliding proximally and collapsing the distal anchor 254when positioned in a vessel.

[0057] As shown in FIG. 11, a distal anchor 256 is constructed in afashion similar to the proximal anchor 140 shown in FIG. 3. That is, theproximal anchor 256 is formed of a separate wire than the wire used toform the support wire 252 and distal anchor 254. The wire of theproximal anchor has one end within a proximal crimp tube 270. The wireextends distally out of the end of the crimp tube and bends radiallyoutward before returning back and across the longitudinal axis of thecrimp tube 270. At the proximal end of the crimp tube 270, the wire ofthe proximal anchor forms a double eyelet 272 around the longitudinalaxis of the support wire 252. The wire then continues radially outwardand distally over the longitudinal axis of the crimp tube 270 to formthe second leg of the figure eight whereupon it is bent proximally intothe distal end of the crimp tube 270.

[0058]FIG. 12 shows yet another embodiment of an intravascular supportin accordance with the present invention. Here, an intravascular support300 comprises a support wire 302, a distal anchor 304 and a proximalanchor 306. As in the embodiment shown in FIG. 9, the distal anchor 304and the support wire 302 are formed of the same wire. To form the distalanchor, the wire extends distally through a distal crimp tube 310 andexits out the distal end before extending radially outward and bendingback and across the longitudinal axis of the crimp tube 310 to form oneleg of a figure eight. The loop then forms an eyelet 312 around thelongitudinal axis of the support wire 302 before bending radiallyoutward and distally across the longitudinal axis of the crimp tube 310to form a second leg of the figure eight. The wire then enters thedistal end of the crimp tube 310 in the proximal direction. The supportwire 302 may have one or two outwardly extending sections that form adistal stop 314 to maintain the position of the eyelet 312 once thedistal anchor is set in the expanded configuration.

[0059] The proximal anchor 306 is formed from a separate wire as shownin FIG. 14. The wire has one end positioned within the proximal crimptube 320 that extends distally outward and radially away from thelongitudinal axis of the crimp tube 320 before being bent proximally andacross the longitudinal axis of the crimp tube 320 to form one leg ofthe figure eight. The wire then winds around the longitudinal axis ofthe support wire to form an eyelet 322 before being bent distally andacross the longitudinal axis of the crimp tube 320 to enter the distalend of the crimp tube 320 in the proximal direction. As will beappreciated, the proximal crimp tube 320 of the embodiment shown in FIG.12 holds four wires wherein the distal crimp tube 310 need only hold twowires.

[0060] FIGS. 15-18 show other embodiments of the invention. In theembodiment shown in FIG. 15, the intravascular support has an anchor 400formed as a loop 404 emerging from a window 406 in a crimp tube 408.Extending from one end 411 of crimp tube 408 is a support strut 410which connects with loop 404. Also extending from the crimp tube 408 isa support wire 412. Loop 404 and support 410 may be formed from nitinol,stainless steel, or any other appropriate material. The intravascularsupport includes another anchor. The intravascular support of thisembodiment may be delivered and deployed in the manner discussed abovewith respect to the embodiment described above.

[0061]FIG. 16 shows another embodiment of an anchor 450 for anintravascular support. Anchor 450 is formed from two loops 452 and 454emerging from a window 456 and an end 457 of a crimp tube 458. A supportwire 462 also extends from the crimp tube. Loops 452 and 454 may beformed from nitinol, stainless steel, or any other appropriate material.The intravascular support includes another anchor. The intravascularsupport of this embodiment may be delivered and deployed in the mannerdiscussed above with respect to the embodiment described above.

[0062]FIG. 17 shows yet another embodiment of an anchor 500 for anintravascular support according to this invention. Anchor 500 is formedfrom two loops 502 and 504 emerging from a window 506 and an end 507 ofa crimp tube 508. A cross strut 505 connects the loops. A support wire512 also extends from the crimp tube. Loops 502 and 504 and strut 505may be formed from nitinol, stainless steel, or any other appropriatematerial. The intravascular support includes another anchor. Theintravascular support of this embodiment may be delivered and deployedin the manner discussed above with respect to the embodiment describedabove.

[0063]FIG. 18 is a modification of the embodiment shown in FIGS. 3-7. Inthis embodiment, torsional springs 558 of proximal anchor 550 have beenformed as single loops or eyelets in the anchor's wire 552. Thesesprings make the anchor 550 more compliant by absorbing some of theforce applied to the anchor during locking. While FIG. 18 shows aproximal anchor with two springs 558, any number of springs could beused on either the proximal or the distal anchor.

[0064] While the preferred embodiment of the invention has beenillustrated and described, it will be appreciated that various changescan be made therein without departing from the spirit and scope of theinvention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
 1. A device for modifying the shape of tissue adjacent to a lumen, the device comprising: an anchor adapted to securely contact a lumen wall when the device is deployed in a lumen, a reshaper extending from the anchor and adapted to contact the lumen wall when the device is deployed in the lumen to modify the shape of tissue adjacent to the lumen wall; the anchor being expandable within the lumen from a first configuration to a second configuration such that the anchor's diameter perpendicular to the central axis of the lumen in the second configuration is at least 50% greater than the anchor's diameter perpendicular to the central axis of the lumen in the first configuration.
 2. The device of claim 1 further comprising a lock adapted to resist the return of the anchor from the second configuration to the first configuration.
 3. The device of claim 1 wherein the anchor is further adapted to expand from the first configuration to the second configuration after being deployed from a catheter.
 4. The device of claim 1 wherein the anchor is further adapted to be recaptured by a catheter after being deployed from a catheter.
 5. The device of claim 4 wherein the anchor is adapted to change shape to fit within a catheter in response to a recapture force applied to the anchor.
 6. The device of claim 5 wherein the recapture force is less than 20 lbs.
 7. The device of claim 1 wherein the anchor is further adapted to expand to a third configuration as the lumen distends.
 8. The device of claim 1 wherein the anchor is a first anchor, the device further comprising a second anchor, the reshaper extending from the first anchor to the second anchor.
 9. A method of modifying the shape of tissue adjacent to a lumen, the method comprising: providing a device in a catheter, the device comprising an anchor and a reshaper extending from the anchor; inserting a distal end of the catheter into a lumen; and deploying the device from the distal end of the catheter into the lumen, the deploying step comprising: expanding the anchor to contact a lumen wall, the anchor expanding from a first configuration to a second configuration such that the anchor's diameter perpendicular to the central axis of the lumen in the second configuration is at least 50% greater than the anchor's diameter perpendicular to the central axis of the lumen in the first configuration; and placing the reshaper in contact with the lumen wall to modify the shape of tissue adjacent to the lumen wall.
 10. The method of claim 9 wherein the placing step comprises: applying a proximally-directed force to the anchor and the reshaper.
 11. The method of claim 9 further comprising locking the anchor.
 12. The method of claim 9 wherein the anchor is a first anchor and the device further comprises a second anchor, the method further comprising: expanding the second anchor from a first configuration to a second configuration such that the anchor's diameter perpendicular to the central axis of the lumen in the second configuration is at least 100% greater than the anchor's diameter perpendicular to the central axis of the lumen in the first configuration.
 13. The method of claim 12 further comprising locking the second anchor.
 14. The method of claim 12 further comprising: recaptured the device into a catheter.
 15. The method of claim 9 further comprising: recapturing the anchor into a catheter.
 16. A device for modifying the shape of tissue adjacent to a lumen, the device comprising: an anchor adapted to securely contact a lumen wall when the device is deployed in a lumen; and a reshaper extending from the anchor and adapted to contact the lumen wall when the device is deployed in the lumen to modify the shape of tissue adjacent to the lumen wall, the anchor being deployable to a deployed configuration within the lumen such that the anchor's open cross-sectional area measured perpendicular to a central axis of the lumen is at least 50% of the lumen cross-sectional area.
 17. The device of claim 16 further comprising a lock adapted to maintain the anchor in the deployed configuration.
 18. The device of claim 16 wherein the anchor is adapted to expand to the deployed configuration after being deployed from a catheter.
 19. The device of claim 18 wherein the anchor is further adapted to be recaptured by a catheter after being deployed from the catheter.
 20. The device of claim 18 wherein the anchor is adapted to change shape to fit within a catheter in response to a recapture force applied to the anchor.
 21. The device of claim 20 wherein the recapture force is less than 20 lbs.
 22. The device of claim 16 wherein the anchor is further adapted to expand as the lumen distends.
 23. The device of claim 16 wherein the anchor is a first anchor, the device further comprising a second anchor, the reshaper extending from the first anchor to the second anchor.
 24. A method of modifying the shape of tissue adjacent to a lumen, the method comprising: providing a device in a catheter, the device comprising an anchor and a reshaper extending from the anchor; inserting a distal end of the catheter into a lumen; and deploying the device from the distal end of the catheter into the lumen, the deploying step comprising: expanding the anchor to contact a wall of the lumen, the anchor expanding from a first configuration to a second configuration such that the anchor's open cross-sectional area measured perpendicular to a central axis of the lumen is at least 50% of the lumen cross-sectional area; and placing the reshaper in contact with the lumen wall to modify the shape of tissue adjacent to the lumen wall.
 25. The method of claim 24 wherein the placing step comprises: applying a proximally-directed force to the anchor and the reshaper.
 26. The method of claim 24 further comprising locking the anchor.
 27. The method of claim 24 further comprising recapturing the device into a catheter.
 28. A device for modifying the shape of tissue adjacent to a lumen, the device comprising: first and second anchors, each adapted to securely contact a lumen wall when the device is deployed in a lumen; and a reshaper extending proximally from the first anchor to the second anchor and adapted to contact the lumen wall when the device is deployed in the lumen to modify the shape of tissue adjacent to the lumen wall, the first and second anchors and the reshaper providing metal coverage within the lumen of less than 30%.
 29. The device of claim 28 wherein the reshaper is adapted to contact the lumen wall when the device is deployed in the lumen.
 30. The device of claim 28 wherein the device is adapted to modify the shape of tissue adjacent to the lumen when a proximally-directed force is applied to the first anchor through the reshaper.
 31. The device of claim 28 wherein the first and second anchors are adapted to expand from a first configuration to a second configuration after being deployed from a catheter.
 32. The device of claim 31 further comprising a lock adapted to resist the return of the anchor from the second configuration to the first configuration.
 33. The device of claim 28 wherein the anchor is further adapted to be recaptured by a catheter after being deployed from a catheter.
 34. The device of claim 33 wherein the anchor is adapted to change shape to fit within a catheter in response to a recapture force applied to the anchor.
 35. The device of claim 34 wherein the recapture force is less than 20 lbs.
 36. A method of modifying the shape of tissue adjacent to a lumen, the method comprising: providing a device in a catheter, the device comprising first and second anchors and a reshaper extending from the first anchor to the second anchor; inserting a distal end of the catheter into a lumen; and deploying the device from the distal end of the catheter into the lumen, the deploying step comprising: expanding the first anchor to contact a wall of the lumen; placing the reshaper in contact with the lumen wall to modify the shape of tissue adjacent to the lumen wall; expanding the second anchor; the first and second anchors and the reshaper providing metal coverage within the lumen of less than 30%.
 37. The method of claim 36 wherein the placing step comprises: applying a proximally-directed force to the first anchor and the reshaper.
 38. The method of claim 36 further comprising locking the first and second anchors.
 39. The method of claim 36 further comprising recapturing the device into a catheter.
 40. A device for modifying the shape of tissue adjacent to a lumen, the device comprising: first and second anchors each adapted to expand to securely contact a lumen wall when the device is deployed in a lumen, the lumen having a lumen volume; a reshaper extending between the first and second anchors and adapted to contact the lumen wall when the device is deployed in the lumen to modify the shape of tissue adjacent to the lumen wall; the device occupying between about 1.5% and about 5.5% of the lumen volume.
 41. The device of claim 40 further comprising first and second anchor locks.
 42. The device of claim 40 wherein the first and second anchors are further adapted to be recaptured by a catheter after being deployed by a catheter.
 43. The device of claim 42 wherein the anchor is adapted to change shape to fit within a catheter in response to a recapture force applied to the anchor.
 44. The device of claim 43 wherein the recapture force is less than 20 lbs.
 45. A device for modifying the shape of tissue adjacent to a lumen, the device comprising: an anchor adapted to securely contact a lumen wall when the device is deployed in a lumen, the lumen having a lumen volume; a reshaper extending from the anchor and adapted to contact the lumen wall when the device is deployed in the lumen to modify the shape of tissue adjacent to the lumen wall; the device occupying between about 1.5% and about 5.5% of the lumen volume.
 46. The device of claim 45 wherein the anchor is further adapted to expand within the lumen from a first configuration to a second configuration.
 47. A method of modifying the shape of tissue adjacent to a lumen, the method comprising: delivering a device into a lumen volume within the lumen, the device comprising an anchor and a reshaper extending from the anchor, the device occupying between about 1.5% and about 5.5% of the lumen volume; placing the anchor in secure contact with a lumen wall; and placing the reshaper in contact with the lumen wall to apply force to the lumen wall to modify the shape of tissue adjacent to the lumen wall.
 48. The method of claim 47 wherein the step of placing the anchor comprises expanding the anchor.
 49. The method of claim 47 wherein the anchor is a first anchor and the device further comprises a second anchor, the method further comprising placing the second anchor in secure contact with a lumen wall.
 50. The method of claim 49 wherein the step of placing the second anchor comprises expanding the second anchor.
 51. The device of claim 47 wherein the lumen is a coronary sinus, the step of placing an anchor comprising placing an anchor in secure contact with a wall of the coronary sinus, the step of placing a reshaper comprising placing a reshaper in contact with the coronary sinus wall to apply force to the posterior of a mitral valve annulus through the coronary sinus wall. 